Clinical Guidance
Activated PI3K delta syndrome (APDS) is a rare inborn error of immunity characterized primarily by frequent infections, lymphoproliferation, and autoimmune manifestations. To date, at least 250 individuals have been identified with a pathogenic variant in PIK3CD (for APDS1) or PIK3R1 (for APDS2) [, , , , ]. The following description of the phenotypic features associated with this condition is based on these reports. It is important to note that the severity and presence of these clinical findings can vary widely among affected individuals. Some may present with mild symptoms, while others experience severe manifestations that significantly impact quality of life. The variability within the spectrum of APDS highlights the importance of individualized care and management strategies. Table 2. Activated PI3K Delta Syndrome: Frequency of Select Features
Feature | % of Persons w/Feature | Comment |
|---|
Sinopulmonary infections | 96%-100% | Severe /or recurrent |
Bronchiectasis | 18%-60% | — |
Lymphoproliferation | 71%-89% | Incl splenomegaly, hepatomegaly, lymphadenopathy |
Growth delays | 45%-62% | — |
Herpes virus infections | 36%-49% | Persistent, severe, /or recurrent |
Enteropathy | 25%-51% | Lymphoid aggregates may be seen on histology. |
Lymphoma | 12%-28% | Particularly early onset |
Autoimmune cytopenias | 19%-30% | May be refractory to conventional therapy |
Autoimmune autoinflammatory disease | 17%-42% Neurodevelopmental delay | 19%-31% |
Source: GeneReviews — "Activated PI3K Delta Syndrome"
